Sleeve valves used for water chambers or water tanks serving as pressure reducing chambers are usually connected to a high-pressure water inlet elbow secured to the upper wall of the chamber. Such sleeve valves comprise a valve cylinder gate having open ends and fitted in the end of the inlet elbow vertically slidably in intimate contact with the inner surface of the elbow, and a cylindrical valve body fitted around the lower portion of the valve cylinder gate and secured to the upper wall of the chamber, the valve body having a number of discharge ports in its peripheral wall and a bottom cover closing its lower end, so as to regulate the flow of water to be discharged from the inlet elbow by controlling the open area between the bottom cover and the lower end of the gate.
Although the valve body of the sleeve valve is fixed at its upper end to the upper wall of the chamber, the lower end of the valve body is liable to move because it is unsupported and merely extends downward within the reducing chamber. Thus the valve involves the problem that the water vigorously flowing out from between the lower end of the gate and the valve seat vibrates the valve body and, accordingly, the whole valve.
Since the sleeve valve has a closed structure in which the upper end of the valve body is adapted to be attached to the upper wall of a tank or chamber, foreign matter or solids in water tend to accumulate on the bottom cover, thus entailing the necessity of periodically cleaning the interior of the valve body. However, when the water chamber or tank equipped with a sleeve valve is built underground and used as embedded in the earth as is often practiced, the cleaning operation requires very great labor for excavation and disassembly of the valve.